a. Field of Invention
The invention relates generally to fuel injectors, and, more particularly to an improved apparatus and method for delivering fuel via fuel injectors, and electrically wiring fuel injectors in an internal combustion engine.
b. Description of Related Art
Modern internal combustion engines generally include electronic fuel injectors for delivering fuel into the combustion chamber. Known fuel injector types include, for example, top, bottom and side feed fuel injectors in which fuel is respectively delivered adjacent the top, bottom or side of the fuel injector.
Conventional top feed fuel injectors generally require a bulky electrical connector mounted adjacent to the top of the injector body. These bulky electrical connectors increase assembly complexity and consume valuable space needed for component packaging. During engine repair or manufacturing, conventional electrical connectors can often be difficult to access. Moreover, conventional injector wiring harnesses can be difficult to secure in the compact engine spaces, are often poorly defined due to the lack of adequate spacing, and may themselves unnecessarily consume packaging space.
As engine s become increasingly complex and compact, the space available for mounting fuel injectors, fuel rails, and electrical wiring harnesses becomes increasingly limited.
Various conventional very systems and electrical connectors for fuel injectors are known and disclosed, for example, in U.S. Pat. No. 6,338,333 to Brosseau et al. ( grosseau) and U.S. Pat. No. 6,260,537 to Lamb et al. ( Lamb).
U.S. Pat. No. 6,338,333 to Brosseau discloses an integrated fuel delivery system for fuel injectors in an internal combustion engine. Brosseau however does not address the electrical connections to fuel injectors or the wire harness layout, which factor into the drawbacks of today""s conventional fuel injection system designs. U.S. Pat. No. 6,260,537 to Lamb discloses bottom feed fuel injectors with electrical wiring connections on top. As for Brosseau, Lamb also does not simplify electrical connections for fuel injectors so as to facilitate the installation and testing thereof.
For the U.S. Patents cited above, from a design and manufacturing standpoint, the manufacture of the relatively complicated fuel delivery and electrical connection systems of the past has resulted in a noticeable increase in the overall manufacturing cost of vehicles, which are typically manufactured by the hundreds of thousands. From an assembly standpoint, the assembly and installation of complex electrical connectors and wiring harnesses can be time-consuming and burdensome, and can further add to the overall cost of a vehicle. Lastly, from a maintenance and use standpoint, improvements in conventional electrical connectors and fuel delivery systems of today""s internal combustion engines would likewise provide improvement in the durability of such engines.
The invention solves the problems and overcomes the drawbacks and disadvantages of the prior art fuel injection systems by providing an integrated fuel delivery and electrical connection system for fuel injectors in an internal combustion engine.
Thus, an aspect of the present invention is to provide a fuel delivery system which incorporates the electrical contacts of a conventional electrical connector into the fuel rail assembly.
Another aspect of the present invention is to provide fuel injectors having integral electrical connections for contact with the electrical contacts on the fuel delivery system of the present invention.
Yet another aspect of the present invention is to eliminate or substantially reduce the need for external wire harness routing.
Another aspect of the present invention is to provide a single point wiring harness connection for electrical connection to the fuel injectors.
Yet another aspect of the present invention is to provide a method for testing fuel injection systems before final engine assembly, and simplifying injector installation and removal.
The invention accomplishes these aspects by providing an integrated fuel delivery and electrical connection system generally including an electrical bus, a fuel delivery tube and fuel injectors. The electrical bus may include openings for insertion and connection of fuel injectors. The electrical bus may further include positive electrical contacts for electrical connection to a respective fuel injector positive electrical contact and ground contacts for grounding a fuel injector ground contact. The fuel delivery tube may include openings for insertion and connection of fuel injectors, and may be connected to the electrical bus. A portion of each of the fuel injectors may be inserted into each of the openings in the electrical bus and fuel delivery tube to thereby connect each fuel injector to the electrical bus and fuel delivery tube.
For the fuel delivery and electrical connection system described above, each of the positive electrical contacts in the electrical bus may be mounted at a first radial distance from a central longitudinal axis of the electrical bus and the ground contact in the electrical bus may be mounted at a second radial distance from the central axis. The first radial distance may be less than the second radial distance, greater than the second radial distance, or approximately equal to the second radial distance. The electrical bus may further include an electrical environmental seal for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the positive and ground contacts on the fuel injector. A plurality of electrical wires may be connected to each of the positive and ground contacts in the electrical bus and terminate at a generally single connection point on the electrical bus. The electrical bus and the fuel delivery tube may be fabricated as a single unit or as separate components of an assembly. The fuel injector positive electrical contact may be mounted at a first axial distance from a fuel injector end surface along a fuel injector central longitudinal axis and the fuel injector ground contact may be mounted at a second axial distance from the fuel injector end surface along the fuel injector central longitudinal axis. The first axial distance may be less than the second axial distance, greater than the second axial distance, or approximately equal to the second axial distance. The fuel injector positive and ground contacts may each be located at a predetermined location along the fuel injector central longitudinal axis and disposed substantially along opposite surfaces of the fuel injector. The fuel injector may further include an electrical environmental seal for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the fuel injector positive and ground contacts.
The present invention also provides a method of installing an integrated fuel delivery and electrical connection system in an internal combustion engine. The method may include the step of inserting fuel injectors into an opening in an electrical bus. The electrical bus may include positive electrical contacts for electrical connection to fuel injector positive electrical contacts and ground contacts for grounding fuel injector ground contacts. The method may further include the step of connecting the electrical bus and fuel injectors to a fuel delivery tube. The fuel delivery tube may include corresponding openings for insertion and connection of the fuel injectors. The method may yet further include the step of connecting a single electrical harness to the electrical bus to provide electricity to the system.
For the method described above, the method may further include the steps of affixing the positive electrical contact in the electrical bus at a first radial distance from a central longitudinal axis of the electrical bus and affixing the ground contact in the electrical bus at a second radial distance from the central longitudinal axis. The first radial distance may be less than the second radial distance, greater than the second radial distance, or approximately equal to the second radial distance. The method may further include the step of providing an electrical environmental seal in the electrical bus for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the fuel injector positive and ground contacts. The electrical bus may be made of a non-conductive material such as plastic. The method may further include the steps of connecting electrical wires to each of the positive and ground contacts in the electrical bus. The electrical wires may terminate at a generally single connection point on the electrical bus. The electrical bus and the fuel delivery tube may be fabricated as a single unit or as separate components. The method may further include the steps of affixing the positive electrical contact on the fuel injector at a first axial distance from a fuel injector end surface along a fuel injector central longitudinal axis, and affixing the ground contact on the fuel injector at a second axial distance from the fuel injector end surface along the fuel injector central longitudinal axis. The first axial distance may be less than the second axial distance, greater than the second axial distance, or approximately equal to the second axial distance. The method may further include the step of providing the fuel injector with an electrical environmental seal for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the fuel injector positive and ground contacts.
Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation with out limiting the scope of the invention as claimed.